Package forming mechanism



April 7, 1964 J. E. WOOLSEY 3,127,819

PACKAGE FORMING MECHANISM Filed Dec. 50, 1960 2 Sheets-Sheet l l i 1 46 Q I dob/7 F WOO/J e5] 1 INVENTOR. JA 1/ April 7 9 4 J. E. WOOLSEY 3,127,819

PACKAGE FORMING MECHANISM Filed Dec. 30, 1960 2 Sheets-Sheet 2 IN V EN TOR.

ATTO/P/VEV M060 A. Woo/Jay United States Patent 3,127,819 PACKAGE FORMING MECHANISM John E. Wo'oisey, 1540 Kirby Drive, Houston, Tex. Filed Dec. 30, 1969, Ser. No. 79,670 1 Qlaim. (8!. 93-82) This invention relates to packaging apparatus, and more particularly to mechanism for carrying out a packaging process which includes forming a continuous strip of flexible material into a tube, introducing the product to be packaged into the tube and closing the tube at spaced intervals to form the same into a series of filled bags.

The invention finds particular application in connection with the packaging of various products suitable for enclosure in bags, the packaging being carried out by a continuous process in which a strip of flexible material is formed into a tubular shape, the product loaded therein, and the tube closed and cut at longitudinally spaced intervals to complete the bags.

A number of diflerent types of packaging apparatus have been proposed heretofore for this purpose. One such apparatus commonly used making use of an inner tubular mandrel supported in radially, inwardly spaced concentric relation to an outer tube, a strip of flexible material being fed into the outer tube between the same and the inner mandrel to form the strip into a continuous tube, and the product to be packaged being introduced into the tube through the mandrel. Means is provided for closing the tube at longitudinally spaced intervals as the same is shaped and filled to form filled bags. In packaging mechanism of this type, the inner tubular mandrel is of substantially smaller diameter than the tube of flexible material which is formed, so that the filling of the bags is limited by the size of the mandrel and when such mechanism is used for the packaging of products having particles or pieces of widely varying sizes, clogging of the mandrel frequently occurs.

Another type of apparatus widely used for this purpose is constructed without the inner mandrel, the outer tube being provided with a former or shoe over which the strip of flexible material is pulled into the tube to form the material into a tubular shape. At the location where the strip of packaging material passes over the former and enters the interior of the tube, a sharply defined edge must be provided for the transition of the material, from the exterior to the interior of the tube, to prevent wrinkling or other deformation of the material. The edge over which the material passes into the tube in this form of apparatus must also be kept extremely sharp to avoid wrinkling or damage to the flexible strip which greatly increases the expense of repair and maintenance of the equipment.

The present invention has for an important object the overcoming of the above described objectionable features of previous packaging equipment of the kind referred to by the provision of package forming mechanism which makes it unnecessary to employ an inner mandrel, and in which the transition of the flexible strip material from the exterior to the interior of the former tube takes place gradually without passing the material over sharp edges or other structures likely to cause wrinkling, grooving or other distortion or damage to the material.

Another object of the invention is the provision of package forming mechanism of the kind mentioned in which the full cross-sectional area of the tubular receptacle formed is available for use in filling a product into the receptacle.

A further object of the invention is to provide forming mechanism for flexible sheet material for the making of bags, which is constructed for guiding engagement throughout the entire Width of the material during the entire time that the material is moving through the forming mechanism, to support the material and hold the same against wrinkling or distortion during the entire movement of the material through the shaping mechanism.

Another object of the invention is to provide a former for flexible sheet material, for use in shaping an elongated strip of material into a tubular shape, and which is constructed with a widened material engaging portion which is curved in the direction of longitudinal movement of the material through the forming mechanism, positioned for engagement with one face of the material, and elongated, curved material engaging portions which are curved laterally of the direction of movement of the material through the forming mechanism positioned for engagement with the other face of the material as the material moves through the forming mechanism to form the material into a tubular shape.

A further object of the invention is the provision in package forming mechanism of guiding; and shaping means having an end surface portion shaped for engagement with a strip of flexible material throughout its entire width to guide the material in a curved longitudinal path and curved side surface portions shaped to engage side portions of the strip to guide and curve the material laterally to curve the material into a tubular shape as the material moves longitudinally through the mechanism.

Another object of the invention is to provide package forming mechanism for use with a strip of flexible sheet material embodying curved surface portions positioned for engagement with the material to guide and shape the material into a tubular shape, said surface portions being positioned to cause a smooth transition of the material from a flat shape to a tubular shape without passing the material over sharp edges or structures likely to cause distortion of the material.

A still further object of the invention is to provide package forming mechanism for flexible sheet material which is of simple design and economical manufacture, having long wearing qualities and which is easily maintained in condition for perfect operation.

The above and other important objects and advantages of the invention may best be understood from the following detailed description constituting a specification of the same, when considered in conjunction With the annexed drawings, wherein- FIGURE 1 is a fragmentary, side elevational view, partly broken away and on a reduced scale, illustrating a preferred embodiment of the invention and showing the manner in which the packaging material moves through the mechanism during the forming operation;

FIGURE 2 is a perspective view of the material forming mechanism of the invention, as illustrated in FIG- URE 1;

FIGURE 3 is a diagrammatic view, on a somewhat enlarged scale, illustrating the layout of the parts of the material forming mechanism and showing the manner in which the same may be constructed from a flat sheet of material;

FIGURE 4 is a front view on a somewhat enlarged scale of the forming mechanism of the invention, as illustrated in FIGURE 2;

FIGURE 5 is a side, elevational view of the forming mechanism of FIGURE 4, partly broken away and partly in cross-section;

FIGURE 6 is a top plan view of the forming mechanism, as illustrated in FIGURE 4.

Referring now to the drawings in greater detail, the invention is disclosed herein in connection with its use in i the making of bag-like packages from flexible sheet material, such as paper, plastic film, or the like, which are filled and closed by a continuous process. The mechanism of the invention comprises generally a forming head or shoe, generally designed 10, constructed in several parts, through which a continuous strip 12 of flexiblesheet material is passed from a rotatably supported roll 14 of such material, from which the material may be fed into the former head over suitably located rollers 16 and 18, the material being pulled downwardly through the former head by mechanism of conventional design, not shown, to shape the material into a tubular formation, as shown at 20 in FIGURE 1, the product to be packaged being meanwhile fed into the interior of the former head and downwardly into the tubular receptacle thus formed, by any suitable feeding mechanism of conventional construction, not shown, and means being provided, such as that indicated at 22, for closing, sealing and cutting off the tubular receptacle at longitudinally spaced intervals, as shown in FIGURE 1, to complete the bags with the contents therein.

Suitable means is also provided, such as the back-up bar 24 and heater element 26, located to permit the passage therebetween of overlapping, longitudinally extending portions of the material when the same has been formed into a tubular shape, to seal such overlapping portions together to complete the tube. The material feeding, sealing mechanism, and mechanism by which the flexible material is pulled through the former is of wellknown construction, commonly used in packaging machinery of this kind, and the details of these portions of the packaging machine are not shown herein, since they form no part of the present invention, except as they are associated with the forming head by which the flexible material is shaped into a tubular structure.

The forming head or shoe is preferably formed in three pieces 28, 3t) and 32, of which the part 28 is a central or back member and the parts 30 and 32 are side or wing members. The central part 28 has a widened, upper end 34 andis formed with a downwardly tapering,

longitudinally curved face 36, which terminates at its wardly tapering, upper end portion 42, which terminates in an upwardly directed point 44, and is formed with a lower'end portion 46 which is curved to form a portion of a cylinder, the portions 40 and the portions 46 of the central and side members being shaped to provide a sec- 'tionof substantially complete tubular shape at the lower end of the forming head when the parts are assembled.

'Iihe part'28 is suitably supported in an upright position, as by means of a bracket 48 attached thereto, which is connected at its outer end to any suitable supporting structure, not shown, to hold the central part in a fixed position, and each of the side or wing parts 30 or 32 is provided with a laterally extending foot portion 50, which is suitably perforated for attachment to any desired supporting structure, as by means of brackets 51, shown in FIGURE 1, to hold the wings in assembled relation to the 'central part 28, but slightly spaced therefrom, to provide longitudinally extending slots 52' extending from end to end through the'forming head, as best seen in FIGURES 1 and 4, and through which the flexible strip 12 may pass during the forming operation.

.The slots 52 have'straight, lower end portions 54, in the region of the curved portions 40 and 46 of the central part '28 and wings 30* and 32, as best seen in FIG- URES 2 and 4, while the portions of the slots 52 above these lower end portions 54 diverge upwardly.

The forming head parts 28, 3t) and 32 may conveniently be constructed from sheet metal, the parts being cut from a flat sheet in the manner illustrated in FIGURE 3, and thereafter shaped to the proper curvatures to be assembled as described above, to provide the longitudinal slots 52, the central, longitudinally curved, downwardly tapering face 32, the wing portions 42 and the curved por- 4 tions 40 and 46 which provide the tubular shaped lower end portion of the forming head.

The parts are preferably fashioned as illustrated in FIGURE 3, wherein it will be seen that the portion of the downwardly tapering, longitudinally curved face 32, located between the lower end curved portions 40 of the central part 28 is of a width at the location of the upper ends of the curved portions 40 which is substantially equal to the diameter of the cylindrical lower end of the forming head. This downwardly tapering, longitudinally curved, lower face portion will have an area equal to a V-shaped portion cut out of a cylinder of the same diameter as the cylindrical lower end of the forming head, which V-shaped portion at its upper end has a width substantially less than the length of an are less than degrees. Thus, the width of this downwardly tapering, longitudinally curved lower end surface portion of the central part 28 is the same as the length of the arc represented by the lower ends of the curved portions 40 of the central part.

In forming the flexible sheet material into a tubular shape, by the use of the forming head of the invention, the sheet material 12 is fed off of the roll 14 over the rollers 16 and 18 and downwardly over the external face 36 of the central part 28, as illustrated in FIGURE 1, the sheet material being turned in at its side edges into the slots 52 and pulled downwardly through the head, so that as the material passes downwardly from the head, an inner face portion of the material will move downwardly in contact with the longitudinal curved face 36 and the external faces of the curved portions 46 of the central part 28, while outer face portions of the material will move downwardly in contact with the inner faces of the wings 30 and 32, and the curved portions 46 of the wings to cause the material to be formed into a cylinder, as shown at 20 in FIGURE 1. During such downward movement of the material through the head, the marginal portions along the edges of the material will be moved into overlapping relation between the back-up bar 24 and the heating element 26, so that as the tubular receptacle thus formed, moves downwardly, these marginal portions will be sealed together.

As the material is thus formed into a tubular shape, the product to be packaged may be fed into the interior of the head into the tubular portion of the material, through the inwardly tapering throat formed by the upper portions of the central and side parts by any suitable feeding mechanism of conventional design, not shown, so

that the product will be deposited in the tubular portion.

It will be readily seen that the inlet end of the throat of the head is of substantially larger area than the discharge end of the same, which is of substantially the same area as the tubular portion of the sheet material being formed, so that the filling of the packages can be accomplished rapidly as the same are formed. When the material has been thus initially drawn through the head, the material feeding and sealing mechanism 22 may then be operated to pinch in the tubular portion and pull the sheet material downwardly a predetermined distance to form one package, this mechanism also sealing the lower end of one such bag and the upper end of the next lower bag and cutting the bags apart as they are thus closed to complete the filled packages. The above described flexible -material feeding, sealing and cutting mechanism is of well-known'construction and for purposes of simplicity, the details-of structure and mechanical operation of this. mechanism is not shown herein, since the same forms no part of the present invention.

It will be apparent that because of the fact that the upper end portion of the central part 28 is at least as wide as the material which is being operated upon and the curved portions 40 and 46 at the lower end of the head form a substantially complete cylinder, the material will be at all times supported in passing through the head throughout substantially 360 degrees, so that wrinkling or distortion of the material is prevented, and the material emerging from the lower end of the head will be formed into a uniform tubular shape. Moreover, the transition of the material from a flat strip to a tubular shape takes place gradually as the material passes through the head, so that there is no abrupt change in the direction of bending of the material from longitudinal to lateral, thus assuring a smooth, continuous operation of the mechanism without danger of wrinkling or distorting the material.

The portion of the external face of the central part 23 between the divergent portions of the slots 52 may be made fiat, so that the side edges of the central part in this region will be straight, thus providing edges over which the side margins of the sheet material may be easily turned as the material moves downwardly through the head.

It will thus be seen that the invention constructed and operated as described above, provides package forming mechanism which is of simple design, having few parts, and which is capable of use with flexible sheet material of Widely varying character to package numerous different kinds of products by a continuous and automatic process.

The invention is disclosed herein in connection with a certain specific embodiment of the same, but it Will be understood that various changes can be made in the configuration and arrangement of the parts, within the spirit of the invention and the scope of the appended claim.

Having thus clearly shown and described the invention, what is claimed as new and desired to secure by Letters Patent is:

In packaging mechanism a hollow forming head for flexible sheet material comprising a central part having a longitudinally downwardly tapering outer face positioned for engagement with one face of an elongated strip of flexible sheet material during longitudinal movement of the material over said outer face, side parts on opposite sides of said central part shaped to form with the side edges of said central part longitudinally extending open ended slots through which side marginal portions of said material may be extended to cause said marginal portions to be moved into contact with the inner faces of said side parts during such downward movement, said central part having a laterally curved external surface adjacent its lower end positioned for engagement with said one face of said material and said side portions having laterally curved internal surfaces at their lower ends positioned for engagement with the other face of said material to move the material laterally into a tubular shape as the material emerges from the head and said central and side parts having internal surface portions positioned to form an inwardly tapering throat in communication with the interior of the tubular portion of the material emerging from the head.

References Cited in the file of this patent UNITED STATES PATENTS 2,113,668 Lakso Apr. 12, 1938 2,237,119 Smith Apr. 1, 1941 2,393,329 Maple et a1 Jan. 22, 1946 2,934,130 Lane et al Apr. 26, 1960 

